Information processing apparatus, information processing method, recording medium, playback apparatus, playback method, and program

ABSTRACT

There is provided an information processing apparatus, an information processing method, a recording medium, a playback apparatus, a playback method, and a program that are designed to prevent an unnatural change in luminance during random access. The information processing apparatus according to one aspect of the present technology generates dynamic metadata including information regarding luminance of a picture, and encodes HDR video data such that the dynamic metadata is added to each picture serving as a random access point. For example, the dynamic metadata can be allowed to be added to the first picture of a GOP, the first picture serving as the random access point during fast-forward playback/rewind playback or cueing playback. The present technology can be applied to a Blu-ray (registered trademark) Disc player.

TECHNICAL FIELD

The present technology relates to an information processing apparatus,an information processing method, a recording medium, a playbackapparatus, a playback method, and a program, and particularly relates toan information processing apparatus, an information processing method, arecording medium, a playback apparatus, a playback method, and a programthat are designed to prevent an unnatural change in luminance duringrandom access.

BACKGROUND ART

Ultra HD Blu-ray (registered trademark) Disc (UHD BD) is a BD standardthat supports recording a high dynamic range (HDR) video, which is avideo having an extended dynamic range. While the maximum luminance of astandard dynamic range (SDR) is 100 nits (100 cd/m²), the maximumluminance of an HDR video is higher than that, such as 10,000 nits.

As metadata for an HDR video stream, Dynamic metadata is defined inSMPTE ST 2094, the Dynamic metadata being the metadata includingluminance information on a picture (frame) basis. During playback of anHDR video stream to which Dynamic metadata is added, each picture istransmitted from the player side to the TV side along with Dynamicmetadata.

On the TV side, if the maximum luminance of the display is lower thanthe luminance of the HDR video, a process for compressing the luminanceof the HDR video is performed on the basis of the Dynamic metadatatransmitted from the BD player.

CITATION LIST Patent Document Patent Document 1: Japanese PatentApplication Laid-Open No. 2017-139052 SUMMARY OF THE INVENTION Problemsto be Solved by the Invention

Random access may occur during playback of an HDR video. Random accessrefers to the playback involving a jump over a section, such as specialplayback (trick play), which is fast-forward/rewind playback at x-foldspeed, or chapter jump (cueing playback). When an instruction to performsuch special playback or chapter jump is given by a user, random accessoccurs.

Depending on the state of the destination picture of a jump made forrandom access, such as the state in which no Dynamic metadata is added,an unnatural change in luminance may occur.

The present technology has been made in view of such circumstances, andis intended to prevent an unnatural change in luminance during randomaccess.

Solutions to Problems

An information processing apparatus according to a first aspect of thepresent technology includes: a generation unit that generates dynamicmetadata including information regarding luminance of a picture; and anencoding unit that encodes HDR video data such that the dynamic metadatais added to each picture serving as a random access point.

A playback apparatus according to a second aspect of the presenttechnology includes: a playback unit that performs random accessplayback of a video stream to which dynamic metadata includinginformation regarding luminance of a picture is added; and an outputcontrol unit that, in a case where predetermined information indicatingthat random access playback is being performed is to be superimposed onthe picture and displayed, adds metadata to be used during random accessplayback for luminance adjustment during the random access playback tothe picture serving as a random access point, and outputs the picture towhich the metadata to be used during the random access playback is addedto a display apparatus.

In the first aspect of the present technology, dynamic metadataincluding information regarding luminance of a picture is generated; andHDR video data is encoded such that the dynamic metadata is added toeach picture serving as a random access point.

In the second aspect of the present technology, random access playbackof a video stream to which dynamic metadata including informationregarding luminance of a picture is added is performed; in a case wherepredetermined information indicating that random access playback isbeing performed is to be superimposed on the picture and displayed,metadata to be used during random access playback for luminanceadjustment during the random access playback is added to the pictureserving as a random access point; and the picture to which the metadatato be used during the random access playback is added is output to adisplay apparatus.

Effects of the Invention

According to the present technology, an unnatural change in luminanceoccurring during random access can be prevented.

Note that the effects described above are not restrictive, and any ofeffects described in the present disclosure may be included.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating an example configuration of an HDRcontent playback system.

FIG. 2 is a diagram illustrating an example of a tone curve used forluminance compression on an HDR video.

FIG. 3 is a diagram showing Dynamic metadata defined in SMPTE ST2094-40.

FIG. 4 is a diagram illustrating a BD file structure.

FIG. 5 is a diagram illustrating an example of an AV stream structure.

FIG. 6 is a diagram illustrating an example of transmission of Dynamicmetadata.

FIG. 7 is a diagram illustrating an example of random access playback.

FIG. 8 is a diagram illustrating examples of display provided duringrandom access playback.

FIG. 9 is a diagram illustrating examples of a GOP included in an HDRvideo stream.

FIG. 10 is a diagram illustrating an example of an AV stream managementstructure according to the BD-ROM format.

FIG. 11 is a diagram illustrating structures of a Main Path and a SubPath.

FIG. 12 is a diagram illustrating an example of a file managementstructure.

FIG. 13 is a block diagram illustrating an example configuration of arecording apparatus.

FIG. 14 is a block diagram illustrating an example functionalconfiguration of the controller in FIG. 13.

FIG. 15 is a block diagram illustrating an example configuration of aplayback apparatus.

FIG. 16 is a block diagram illustrating an example configuration of aTV.

FIG. 17 is a flowchart explaining a recording process in a recordingapparatus.

FIG. 18 is a flowchart explaining a playback process in a playbackapparatus.

FIG. 19 is a diagram illustrating an example of an HDR video stream.

FIG. 20 is a diagram showing the syntax of Clip Information.

FIG. 21 is a diagram showing the syntax of CPI( ).

FIG. 22 is a diagram showing the syntax of EP_map( ).

FIG. 23 is a diagram showing the syntax of EP_map_for_one_stream_PID.

FIG. 24 is a flowchart explaining a recording process in a recordingapparatus.

FIG. 25 is a diagram illustrating an example of metadata transmissionoccurring during random access playback.

FIG. 26 is a diagram illustrating displays subsequent to luminancecompression.

FIG. 27 is a block diagram illustrating an example functionalconfiguration of the controller in FIG. 15.

FIG. 28 is a flowchart explaining another playback process in a playbackapparatus.

FIG. 29 is a flowchart explaining a display process in a TV.

FIG. 30 is a diagram illustrating an example of random access playback.

FIG. 31 is a flowchart explaining still another playback process in aplayback apparatus.

FIG. 32 is a diagram illustrating an example configuration of an HDRcontent playback system.

FIG. 33 is a diagram illustrating another example configuration of aplayback apparatus.

FIG. 34 is a diagram illustrating an example configuration of anotherHDR content playback system.

FIG. 35 is a block diagram illustrating an example configuration of acomputer.

MODE FOR CARRYING OUT THE INVENTION

A mode for carrying out the present technology will now be described.Descriptions are provided in the order mentioned below.

1. Metadata for HDR video

2. Luminance change during random access playback

3. First embodiment (example of constraint on encoding)

4. Second embodiment (example in which default metadata is used)

5. Example configuration of playback system

6. Other examples

<<Metadata for HDR Video>>

FIG. 1 is a diagram illustrating an example configuration of an HDRcontent playback system.

The playback system in FIG. 1 includes a playback apparatus 1 and a TV(television receiver) 2 connected to each other by a cable compliantwith a predetermined standard such as High-Definition MultimediaInterface (HDMI) (registered trademark) 2.0a or HDMI 2.1. The playbackapparatus 1 and the TV 2 may also be connected to each other via awireless interface.

The playback apparatus 1 is an apparatus supporting playback of HDRcontent, such as a UHD BD player. A BD on which HDR content is recordedis to be loaded into a drive in the playback apparatus 1. The content tobe played back by the playback apparatus 1 includes audio data as wellas HDR video data.

The TV 2 has a function of displaying a video that has been input fromthe outside, as well as a function of receiving and displaying abroadcast program that has been transmitted through transmission linesincluding broadcast waves and networks. The TV 2 includes a displaydevice that supports displaying an HDR video having a luminance greaterthan 100 nits.

Before transmission of an HDR video is started, the playback apparatus 1and the TV 2 set up an HDMI transmission configuration by, for example,sending and receiving to/from each other the information regarding theirrespective performance capabilities. For example, the playback apparatus1 notifies the TV 2 that an HDR video will be transmitted. Furthermore,the TV 2 notifies the playback apparatus 1 of the maximum luminance ofthe display on the TV 2.

After the transmission configuration, the playback apparatus 1 decodesthe HDR video stream that has been read from the BD and outputsindividual pictures in the HDR video to the TV 2. The TV 2 receives anddisplays the individual pictures transmitted from the playback apparatus1.

During the operation, in the TV 2, a process of adjusting (compressing)the luminance of the HDR video transmitted from the playback apparatus 1is performed as appropriate in accordance with the performancecapability of the display. The luminance compression is performed in acase where the luminance of the HDR video output by the playbackapparatus 1 is higher than the maximum luminance of the display in theTV 2.

The example in FIG. 1 assumes that the luminance of an HDR video outputby the playback apparatus 1 is 1,000 nits and the maximum luminance ofthe display in the TV 2 is 500 nits.

FIG. 2 is a diagram illustrating an example of a tone curve used forluminance compression on an HDR video.

In FIG. 2, the horizontal axis represents the luminance of an inputsignal, while the vertical axis represents the luminance of an output(display). For example, the electro-optical transfer function (EOTF)processing with a Perceptual Quantization (PQ) curve as defined in SMPTEST 2084 is performed on the TV 2 side, and the luminance of an HDR videois compressed so as to fall within a luminance range of the displaywhose maximum luminance is 500 nits.

Note that the point at which the light and dark representation is nolonger linear as indicated by the arrowhead in FIG. 2 is called a kneepoint.

Thus, in the playback system in FIG. 1, in a case where the display inthe TV 2 does not have sufficient luminance relative to the luminance ofan HDR video that is output by the playback apparatus 1, luminancecompression is performed on the TV 2 side.

As supplementary information for luminance compression, metadataincluding information regarding luminance of the content is transmittedfrom the playback apparatus 1 to the TV 2. For example, Dynamic metadatais transmitted from the playback apparatus 1 to the TV 2.

Dynamic metadata, which is the metadata dynamically representinginformation regarding luminance of the content on a picture basis, isstandardized in SMPTE ST 2094.

FIG. 3 is a diagram showing Dynamic metadata defined in SMPTE ST2094-40.

As shown in the first line in FIG. 3, information regarding window(s)that are set in a frame is described in the Dynamic metadata. A windowis a rectangular area that is set in a frame. Up to three windows can beset in a single frame.

For each window that is set in a frame, individual parameters shown inthe 2nd to 14th lines are described.

Window size and Window location indicate the size and location of awindow.

Internal Ellipse size and Internal Ellipse location indicate the sizeand location of an internal ellipse, which is one of two ellipses thatare set in a window. Ellipses are allowed to be set in a window so thatthe luminance in an ellipse can be specified.

External Ellipse size and External Ellipse location indicate the sizeand location of an external ellipse, which is one of two ellipses thatare set in a window.

Rotation angle indicates the inclination of the two ellipses that areset in a window.

Overlap process option indicates the method for processing pixels in anellipse.

maxscl indicates the RGB values of the brightest pixel in a window.

average max rgb indicates the average of maximum R, G, and B values ofindividual pixels in a window.

Distribution max rgb percentages indicates the ranking of the highestluminance in a window as a percentage.

Distribution max rgb percentiles indicates the ranking of the highestluminance in a window as a rank order (percentile).

Fraction bright pixels indicates to what extent the image having themaximum luminance value in a scene is to be output.

Knee point indicates the luminance value at the knee point describedabove.

Bezier curve anchors indicates the sample x,y having brightnessexceeding the knee point.

Color saturation weight indicates the value to be used for correctingRGB values that change during luminance compression on the targetdisplay.

Target System display max luminance indicates the luminance of thetarget display. With Target System display max luminance, it isdetermined that the content has been created on the assumption that thecontent is to be displayed on such display.

Local display luminance indicates the maximum luminance value of each of2×2 areas to 25×25 areas into which the display is divided.

Local mastering display luminance indicates the maximum luminance valueof each of 2×2 areas to 25×25 areas into which the mastering display isdivided.

As seen above, parameters in the 1st to 15th lines in Dynamic metadataindicate attributes of a frame (a window in a frame). Furthermore,parameters in the 16th and 17th lines indicate attributes of the targetdisplay, and a parameter in the 18th line indicates attributes of thedisplay used for creating the content.

FIG. 4 is a diagram illustrating a BD file structure.

An optical disc 11 in FIG. 4 is a recording medium on which the contentof an HDR video is recorded in the BD format.

As described later in detail, an AV stream file with the m2ts extensionis stored in the STREAM directory disposed under the BDMV directory.

An AV stream file is an MPEG-2 TS file obtained by multiplexing,according to MPEG-2, an HDR video stream, an audio stream, a subtitlesstream, and so on. In the example in FIG. 4, AV stream files“01000.m2ts”, “02000.m2ts”, and “03000.m2ts” are stored in the STREAMdirectory.

An HDR video stream is an encoded stream according to, for example, HighEfficiency Video Coding (HEVC). Dynamic metadata is included in an HDRvideo stream as a Supplemental Enhancement Information (SEI) messageaccording to HEVC.

FIG. 5 is a diagram illustrating an example structure of the AV stream“03000.m2ts”, which is enclosed in a frame F1 in FIG. 4.

As shown on the top line in FIG. 5, the AV stream “03000.m2ts” includesTS packets each storing video data, audio data, subtitles data, or thelike. Video TS packets are put together into a Video Elementary stream.

A Video Elementary stream includes an array of Access Units, where eachAccess Unit represents data of a single picture in an HDR video. EachAccess Unit includes an AU delimiter followed by parameters such as SPSand PPS, and also includes an SEI message as enclosed and indicated by aframe F11.

The SEI message includes the aforementioned Dynamic metadata. Note thatHDR video data designated as Picture data is included, following the SEImessage.

In this way, on a BD, Dynamic metadata is included in an HDR videostream in such a way that Dynamic metadata is added to each picture, andthe Dynamic metadata is multiplexed with audio streams and others.

Note that pictures included in an HDR video stream may include a pictureto which no Dynamic metadata is added.

FIG. 6 is a diagram illustrating an example of transmission of Dynamicmetadata.

As illustrated in FIG. 6, Dynamic metadata is associated with eachpicture obtained by decoding an HDR video stream and is transmitted fromthe playback apparatus 1 to the TV 2. In the TV 2, luminance compressionon each picture is performed on the basis of the Dynamic metadatatransmitted along with each picture.

<<Luminance Change During Random Access Playback>>

The playback apparatus 1 has a function of performing random accessplayback, which is a playback method involving random access.

Random access means a jump along a sequence of pictures included in anHDR video stream, the jump being made over the pictures to be playedback from one picture to another picture other than the picturesadjacent to the one picture.

Random access playback includes special playback and cueing playback.Special playback means fast-forward playback/rewind playback at x-foldspeed, where x is a predetermined number, such as 5× or 8× speed. Inaddition, cueing playback means a playback method including jumping to apicture containing a chapter setting or to a picture corresponding to acertain time ahead and starting playback from the jump destinationpicture.

FIG. 7 is a diagram illustrating an example of random access playback.

As an example, the following describes the case where an instruction toperform cueing playback is given at a time when the picture P1 is aboutto be played back, and a jump is made from the picture P1 to the pictureP2 as indicated by the arrow A1 in FIG. 7.

Before the instruction to perform cueing playback is given, theindividual pictures preceding (on the left of) the picture P1 are outputto the TV 2 along with the Dynamic metadata added to the respectivepictures. Furthermore, the picture P1 is output to the TV 2 along withthe Dynamic metadata added to the picture P1.

Furthermore, when an instruction to perform cueing playback is given,the picture P2 is output along with the metadata to be used forluminance compression on the picture P2 on the TV 2 side. Here, in acase where the picture P2 is within a section in which no Dynamicmetadata is added as indicated by the double-headed arrow, any ofvarious types of metadata may possibly be output along with the pictureP2.

For example, it may be possible that, along with the picture P2, theDynamic metadata for the picture P1, from which the jump has been made,is caused to be output from the playback apparatus 1 to the TV 2. Inthis case, luminance compression on the picture P2 is performed in theTV 2 on the basis of the Dynamic metadata for the picture P1.

Furthermore, it may be possible that, along with the picture P2, theDynamic metadata for the picture that has Dynamic metadata added theretoand that immediately precedes the picture P2, namely the picture P3, iscaused to be output from the playback apparatus 1 to the TV 2. In thiscase, luminance compression on the picture P2 is performed in the TV 2on the basis of the Dynamic metadata for the picture P3.

In either case, the picture P2, which is the jump destination picture,may undergo luminance compression not intended by the producer of theHDR content. As a result, the appearance of the picture P2 will bedifferent from the appearance expected by the producer of the HDRcontent.

FIG. 8 is a diagram illustrating examples of display provided duringrandom access playback.

The horizontal axis in FIG. 8 represents time. Pictures P11, P12, andP13 are transmitted from the playback apparatus 1 to the TV 2 in theorder mentioned and undergo luminance compression in the TV 2.

The pictures P11, P12, and P13 are respectively combined with OSD imagesp11, p12, and p13 in the playback apparatus 1 in response to, forexample, an instruction given by the user to perform fast-forwardplayback at 8× speed. In the example in FIG. 8, as an OSD image, animage obtained by combining an image of two triangles representingfast-forward playback with an image of a horizontally long strip withcharacters representing 8× speed is displayed.

A similar OSD image is displayed when an instruction to perform rewindplayback is given. Likewise, when an instruction to perform cueingplayback is given, an OSD image including the jump destination chapternumber or the like is displayed.

For example, suppose that the picture P12 includes a scene with higherluminance than the pictures P11 and P13.

Luminance compression on the picture P11 combined with the OSD image p11is performed on the basis of a tone curve C1 represented by the Dynamicmetadata that has been transmitted along with the picture P11.

Luminance compression on the picture P12 combined with the OSD image p12is performed on the basis of a tone curve C2 represented by the Dynamicmetadata that has been transmitted along with the picture P12. Luminancecompression on the picture P13 combined with the OSD image p13 isperformed on the basis of a tone curve C3 represented by the Dynamicmetadata that has been transmitted along with the picture P13.

The tone curve C2 used for luminance compression on the picture P12including a highly bright scene represents that the luminance is to becompressed more intensely than the tone curve C1 used for luminancecompression on the picture P11 and the tone curve C3 used for luminancecompression on the picture P13. The luminance of the OSD image p12 isalso compressed more intensely than the luminance of the OSD image oneach of the pictures P11 and P13.

Therefore, when the OSD images on the individual pictures subsequent tothe luminance compression are compared in terms of appearance, the OSDimage p12 on the picture P12 is displayed with lower luminance than theOSD images on the pictures P11 and P13, as illustrated in FIG. 8. InFIG. 8, the OSD image p12 shown in lighter color represents that the OSDimage has lower luminance than the OSD images on the pictures P11 andP13.

When the pictures P11 to P13 are sequentially displayed, the luminanceof the OSD image is lowered by one step at a time when the picture P12is displayed, and accordingly the appearance may be unnatural dependingon the degree of luminance compression. For example, in the case ofconsecutive scenes involving greater luminance changes, the OSD imagesmay appear to be blinking.

As seen above, when random access playback is performed on an HDR videostream including Dynamic metadata, the HDR video may look unnatural ifno Dynamic metadata is added to the jump destination picture.Furthermore, an OSD image superimposed on the HDR video may also lookunnatural.

First Embodiment (Example of Constraint on Encoding)

<Example in which Dynamic Metadata is Compulsorily Added to FirstPicture of GOP>

FIG. 9 is a diagram illustrating examples of a GOP included in an HDRvideo stream.

An HDR video stream recorded on the optical disc 11 is an encoded streamaccording to, for example, High Efficiency Video Coding (HEVC) and ismade up of pictures in units of GOP. The example in FIG. 9 shows a GOP 1and a GOP 2.

Among the pictures included in an HDR video stream, Dynamic metadata isadded to at least the picture P1 and the picture P2, which are the firstpicture of the GOP1 and the first picture of the GOP 2, respectively.The picture P1 and the picture P2, each of which is the first picture ofa GOP in terms of display order, are the pictures serving as randomaccess points.

In other words, the HDR video stream recorded on the optical disc 11 isa stream generated under the constraint that Dynamic metadata iscompulsorily added to the picture serving as a random access point.

Fast-forward playback and rewind playback are performed such that, forexample, only the first pictures of their respective GOPs aresequentially played back. The playback apparatus 1 outputs the firstpicture of each GOP to the TV 2, the first picture serving as a randomaccess point, along with the Dynamic metadata added to the first pictureof each GOP.

Furthermore, cueing playback is performed such that playback starts fromthe first picture of a certain GOP. The playback apparatus 1 outputs thefirst picture of a certain GOP to the TV 2, the first picture serving asa random access point, along with the Dynamic metadata added to thepicture.

In the TV 2, luminance compression is performed on the first picture ofa GOP, the first picture serving as a random access point, on the basisof the Dynamic metadata that has been transmitted along with the firstpicture of the GOP. Pictures that have undergone luminance compressionare displayed, whereby fast-forward playback/rewind playback or cueingplayback is fulfilled.

Thus, Dynamic metadata is compulsorily added to the picture serving as arandom access point, which makes it possible to prevent the jumpdestination picture from undergoing luminance compression in a mannernot intended by the producer of the HDR content.

Note that, although it is assumed that HDR video streams recorded on theoptical disc 11 are encoded streams according to HEVC, the HDR videostreams may be generated by encoding in accordance with another methodsuch as AVC (H.264/MPEG-4 Advanced Video Coding (AVC)).

An AVC video stream includes units forming encoding units such as codedvideo sequences (CVSs). AVC video streams are generated by performingencoding under the constraint that Dynamic metadata is compulsorilyadded to the first picture of a CVS, the first picture serving as arandom access point.

Furthermore, instead of being recorded on the optical disc 11, HDR videostreams generated under the constraint that Dynamic metadata iscompulsorily added to the picture serving as a random access point maybe distributed via a network such as the Internet. A configuration of asystem that distributes HDR video streams generated under suchconstraint will be described later.

<BD Format>

Here, the BD-ROM format is described.

—Data Management Structure

FIG. 10 is a diagram illustrating an example of an AV stream managementstructure according to the BD-ROM format.

AV streams are managed by using two layers: PlayList and Clip. AVstreams may be recorded not only on the optical disc 11 but also on alocal storage for the playback apparatus 1.

A pair of one AV stream and its associated information called ClipInformation is managed as one object. A pair of an AV stream and ClipInformation is called a Clip.

An AV stream is extended along a time axis, and the access point of eachClip is specified mainly by a time stamp in a PlayList. Clip Informationis used for purposes including finding an address from which decoding isto be started in an AV stream, for example.

A PlayList is a group of playback sections in an AV stream. A singleplayback section in an AV stream is called a PlayItem. The PlayItem isrepresented by an IN-point and an OUT-point of a playback section on thetime axis. As illustrated in FIG. 10, a PlayList includes one or morePlayItems.

The first PlayList from the left in FIG. 10 includes two PlayItems, andthese two PlayItems reference the first half and the second half,respectively, of the AV stream included in the Clip on the left side.

The second PlayList from the left includes one PlayItem, and the onePlayItem references the entire AV stream included in the Clip on theright side.

The third PlayList from the left includes two PlayItems, and these twoPlayItems respectively reference a certain part of the AV streamincluded in the Clip on the left side and a certain part of the AVstream included in the Clip on the right side.

For example, when the disc navigation program specifies, as the playbacktarget, the left PlayItem included in the first PlayList from the left,the first half of the AV stream included in the left Clip referenced bythe PlayItem is played back.

In a PlayList, a playback path created with an array of one or morePlayItems is called a Main Path. Furthermore, in a PlayList, a playbackpath created with an array of one or more SubPlayItems in parallel witha Main Path is called a Sub Path.

FIG. 11 is a diagram illustrating structures of a Main Path and a SubPath.

A PlayList has one Main Path and one or more Sub Paths. The PlayList inFIG. 11 has one Main Path and three Sub Paths, the Main Path beingcreated with an array of three PlayItems.

Sequential IDs are given to individual PlayItems included in a Main Pathfrom the beginning. Likewise, sequential IDs, that is, Subpath_id=0,Subpath_id=1, and Subpath_id=2, are given to Sub Paths from thebeginning.

In the example in FIG. 11, the Sub Path of Subpath_id=0 includes oneSubPlayItem, and the Sub Path of Subpath_id=1 includes two SubPlayItems.Furthermore, the Sub Path of Subpath_id=2 include one SubPlayItem.

The AV stream referenced by a single PlayItem includes at least a videostream. An AV stream may or may not include one or more audio streams tobe played back at the same timing as (synchronously with) the videostream included in the AV stream.

An AV stream may or may not include one or more bitmap subtitles(presentation graphic (PG)) streams to be played back synchronously withthe video stream included in the AV stream.

An AV stream may or may not include one or more interactive graphic (IG)streams to be played back synchronously with the video stream includedin the AV stream. An IG stream is used for displaying graphics such asbuttons operated by the user.

In an AV stream referenced by a single PlayItem, a video stream ismultiplexed with an audio stream, a PG stream, and an IG stream to beplayed back synchronously therewith.

Furthermore, a single SubPlayItem references a video stream, an audiostream, a PG stream, or the like in a stream different from the AVstream referenced by a PlayItem.

In this way, an AV stream is played back through the use of a PlayListand Clip Information. Playback control information used for managingplayback of an AV stream, namely Index table, PlayList, and ClipInformation, is called Data Base information as appropriate.

—Directory Structure

FIG. 12 is a diagram illustrating an example management structure forfiles recorded on the optical disc 11.

Individual files recorded on the optical disc 11 are hierarchicallymanaged in a directory structure. One root directory is created on theoptical disc 11.

A BDMV directory is placed under the root directory.

Under the BDMV directory, an Index table file named “Index.bdmv” and aMovieObject file named “MovieObject.bdmv” are stored. An Index table isdescribed in the Index table file.

Under the BDMV directory, a PLAYLIST directory, a CLIPINF directory, aSTREAM directory, and others are provided.

The PLAYLIST directory contains PlayList files in which PlayLists aredescribed. Each PlayList file is given a name created by combining afive-digit number with an extension “.mpls”. The three PlayList filesshown in FIG. 12 are given the file names “00000.mpls”, “00001.mpls”,and “00002.mpls”.

The CLIPINF directory contains Clip Information files. Each ClipInformation file is given a name created by combining a five-digitnumber with an extension “.clpi”. The three Clip Information files inFIG. 12 are given the file names “01000.clpi”, “02000.clpi”, and“03000.clpi”, respectively.

The STREAM directory contains files of AV streams as described above.Each AV stream file is given a name created by combining a five-digitnumber with an extension “.m2ts”. The three AV stream files in FIG. 12are given the file names “01000.m2ts”, “02000.m2ts”, and “03000.m2ts”,respectively.

A Clip Information file and an AV stream file that are given the samefive-digit number as a file name constitute a single Clip. When the AVstream file “01000.m2ts” is played back, the Clip Information file“01000.clpi” is used. When the AV stream file “02000.m2ts” is playedback, the Clip Information file “02000.clpi” is used.

<Configurations of Individual Apparatuses>

—Configuration of Recording Apparatus>

FIG. 13 is a block diagram illustrating an example configuration of arecording apparatus 3.

The optical disc 11, which is a BD as described above, is created on therecording apparatus 3 in FIG. 13. The recording apparatus 3 is anapparatus used for authoring of HDR content.

The recording apparatus 3 includes a controller 21, an encodingprocessing unit 22, and a disc drive 23. A master video is input to theencoding processing unit 22.

The controller 21 includes a central processing unit (CPU), a read onlymemory (ROM), a random access memory (RAM), and others. The controller21 executes predetermined programs and controls overall operations ofthe recording apparatus 3.

The encoding processing unit 22 encodes a master video to generate anHDR video stream. The controller 21 supplies the Dynamic metadata thatis to be added to each picture during generation of an HDR stream and isto be encoded into an SEI message.

The encoding processing unit 22 performs the encoding under theconstraint that Dynamic metadata is compulsorily added to the pictureserving as a random access point.

Furthermore, if appropriate, the encoding processing unit 22 generatesan IG stream by encoding a menu image and generates a PG stream byencoding subtitles data. Information including menu images, subtitlesdata, and the like, is also input to the encoding processing unit 22.

The encoding processing unit 22 generates an AV stream that is to formpart of a Clip, by multiplexing the HDR video stream, the IG stream, andthe PG stream, which have been obtained through encoding, with an audiostream and others. The encoding processing unit 22 outputs the generatedAV stream to the disc drive 23.

In accordance with the directory structure in FIG. 12, the disc drive 23records individual Data Base information files supplied from thecontroller 21 and AV stream files supplied from the encoding processingunit 22 onto the optical disc 11.

FIG. 14 is a block diagram illustrating an example functionalconfiguration of the controller 21.

In the controller 21, a Dynamic metadata generation unit 31, an encodingcontrol unit 32, a Data Base information generation unit 33, and arecording control unit 34 are implemented. At least part of thefunctional units illustrated in FIG. 14 is implemented through executionof a predetermined program, the execution being performed by a CPU inthe controller 21.

The Dynamic metadata generation unit 31 sets individual parameters tospecific values in accordance with the input provided by the producer ofthe content and generates Dynamic metadata. The Dynamic metadatageneration unit 31 outputs the generated Dynamic metadata to theencoding control unit 32.

The encoding control unit 32 outputs the Dynamic metadata generated bythe Dynamic metadata generation unit 31 to the encoding processing unit22 and causes the encoding processing unit 22 to encode individualpictures in an HDR video. Furthermore, the encoding control unit 32causes the encoding processing unit 22 to encode menu data and subtitlesdata.

The Data Base information generation unit 33 generates Data Baseinformation including an Index table, a PlayList, Clip Information, andthe like in accordance with the input provided by the producer of thecontent. The Data Base information generation unit 33 outputs filescontaining the generated Data Base information to the recording controlunit 34. The Data Base information generated by the Data Baseinformation generation unit 33 is supplied, as appropriate, to theencoding control unit 32 so that the Data Base information is used forcontrolling the encoding.

The recording control unit 34 outputs files containing the Data Baseinformation generated by the Data Base information generation unit 33 tothe disc drive 23 and causes the disc drive 23 to record the files onthe optical disc 11.

In this way, the recording apparatus 3 functions as an informationprocessing apparatus that generates HDR video streams, by generatingDynamic metadata and performing encoding under the constraint thatDynamic metadata is compulsorily added to the picture serving as arandom access point.

—Configuration of Playback Apparatus

FIG. 15 is a block diagram illustrating an example configuration of theplayback apparatus 1.

The playback apparatus 1 includes a controller 51, a disc drive 52, amemory 53, a local storage 54, a communication unit 55, a decodingprocessing unit 56, an operation input unit 57, and an external outputunit 58.

The controller 51 includes a CPU, a ROM, a RAM, and the like. Thecontroller 51 executes predetermined programs and controls overalloperations of the playback apparatus 1.

The disc drive 52 reads data recorded on the optical disc 11 and outputsthe data to the controller 51, the memory 53, or the decoding processingunit 56. For example, the disc drive 52 outputs the Data Baseinformation read from the optical disc 11 to the controller 51, whileoutputting AV streams to the decoding processing unit 56.

The memory 53 stores data necessary for the controller 51 to executevarious processes, such as programs to be executed by the controller 51.

The local storage 54 includes a recording medium such as a hard diskdrive (HDD) or a solid state drive (SSD). Streams downloaded from aserver and other data are recorded in the local storage 54.

The communication unit 55 is an interface for a wireless LAN, a wiredLAN, or the like. For example, the communication unit 55 communicateswith a server via a network such as the Internet, and supplies datadownloaded from the server to the local storage 54.

The decoding processing unit 56 decodes an HDR video stream multiplexedinto the AV stream supplied from the disc drive 52, and outputs the HDRvideo data obtained through the decoding to the external output unit 58.

Furthermore, the decoding processing unit 56 decodes an audio streammultiplexed into the AV stream, and outputs the audio data obtainedthrough the decoding to the external output unit 58. Although thedescription focuses on video playback, the HDR content played back bythe playback apparatus 1 includes audio data as well.

The operation input unit 57 includes an input device, such as a buttonor a touch panel, and a receiving unit that receives signals, such asinfrared signals transmitted from a remote controller. The operationinput unit 57 detects a user operation and supplies a signalrepresenting specifics of the detected operation to the controller 51.

The external output unit 58 is an interface for external output such asHDMI. The external output unit 58 communicates with the TV 2 via an HDMIcable, and acquires information regarding performance capabilities ofthe display included in the TV 2 and outputs the information to thecontroller 51. Furthermore, the external output unit 58 receives HDRvideo data supplied from the decoding processing unit 56 and outputs thedata to the TV 2.

—Configuration of TV

FIG. 16 is a block diagram illustrating an example configuration of theTV 2.

The TV 2 includes a controller 71, an external input unit 72, a signalprocessing unit 73, a display 74, a broadcast receiving unit 75, adecoding processing unit 76, and a communication unit 77.

The controller 71 includes a CPU, a ROM, a RAM, and the like. Thecontroller 71 executes predetermined programs and controls overalloperations of the TV 2.

For example, the controller 71 manages the information indicatingperformance capabilities of the display 74. During HDMI transmissionconfiguration, the controller 71 outputs the information indicatingperformance capabilities of the display 74 to the external input unit 72to send the information to the playback apparatus 1.

Furthermore, the controller 71 controls the signal processing unit 73 toperform processing of an HDR video. For example, the controller 71causes the signal processing unit 73 to perform luminance compression onan HDR video on the basis of the Dynamic metadata transmitted from theplayback apparatus 1 during playback of the HDR content.

The external input unit 72 is an interface for external input such asHDMI. The external input unit 72 communicates with the playbackapparatus 1 via an HDMI cable, and receives data representing individualpictures in an HDR video transmitted from the playback apparatus 1 andoutputs the data to the signal processing unit 73. Furthermore, theexternal input unit 72 receives the Dynamic metadata transmitted alongwith each picture in an HDR video and outputs the Dynamic metadata tothe controller 71.

The signal processing unit 73 performs processing of the HDR videosupplied from the external input unit 72 so that video images are shownon the display 74. The signal processing unit 73 performs luminancecompression on the HDR video, as appropriate, under the control of thecontroller 71 so that the luminance falls within a range of displaycapabilities of the display 74.

The signal processing unit 73 also performs, for example, a process ofcausing the display 74 to display video images of a broadcast program onthe basis of the data supplied form the decoding processing unit 76.

The display 74 is a display device such as an organicelectroluminescence (EL) display or a liquid crystal display (LCD). Thedisplay 74 displays video images of HDR content, video images of abroadcast program, and so on, on the basis of video signals suppliedfrom the signal processing unit 73.

The broadcast receiving unit 75 extracts broadcast signals of apredetermined channel from the signals supplied from an antenna andoutputs the broadcast signals to the decoding processing unit 76. Thebroadcast receiving unit 75 extracts the broadcast signals under thecontrol of the controller 71.

The decoding processing unit 76 performs processing such as decoding ofthe broadcast signals supplied from the broadcast receiving unit 75 andoutputs video data for a broadcast program to the signal processing unit73.

The communication unit 77 is an interface for a wireless LAN, a wiredLAN, or the like. The communication unit 77 communicates with a servervia the Internet.

<Operations of Individual Apparatuses>

—Operations of Recording Apparatus

Referring to the flowchart in FIG. 17, the following describes arecording process in the recording apparatus 3.

The process in FIG. 17 is started when, for example, the video dataserving as a master is input.

In step S1, the Dynamic metadata generation unit 31 in the controller 21sets individual parameters to specific values in accordance with theinput provided by the producer of the content and generates Dynamicmetadata.

In step S2, the Data Base information generation unit 33 generates DataBase information such as a PlayList.

In step S3, the encoding processing unit 22 encodes the master videounder the control of the encoding control unit 32 and under theconstraint that Dynamic metadata is compulsorily added to the firstpicture of a GOP, the first picture serving as a random access point,and generates an HDR video stream.

Furthermore, the encoding processing unit 22 encodes a menu image andsubtitles data to generate an IG stream and a PG stream. The encodingprocessing unit 22 generates an AV stream by multiplexing the generatedstreams.

In step S4, the disc drive 23 generates the optical disc 11 by recordinga file of the Data Base information supplied from the controller 21 anda file of the AV stream supplied from the encoding processing unit 22.Thereafter, the process is exited.

The foregoing process allows the recording apparatus 3 to generate anHDR video stream in which Dynamic metadata is added to the first pictureof a GOP, the first picture serving as a random access point, and toprovide HDR content including such HDR video stream.

—Operations of Playback Apparatus

Next, referring to the flowchart in FIG. 18, the following describes aprocess in the playback apparatus 1 for playing back the HDR content.

The process in FIG. 18 is started when, for example, the optical disc 11is loaded into the disc drive 52 in the playback apparatus 1 and aninstruction to play back the HDR content is given.

In step S11, the disc drive 52 reads Data Base information filesincluding a PlayList file from the optical disc 11.

In step S12, the controller 51 analyzes the PlayList file to, forexample, identify the AV stream to be played back.

In step S13, the disc drive 52 reads, from the optical disc 11, the AVstream file that includes the HDR video stream to be played back.

In step S14, the decoding processing unit 56 decodes the HDR videostream included in the AV stream supplied from the disc drive 52, andoutputs each picture data piece to the external output unit 58. TheDynamic metadata added to each picture is supplied from the decodingprocessing unit 56 to the controller 51.

In step S15, the external output unit 58 adds the Dynamic metadatasupplied from the controller 51 to each individual picture in the HDRvideo supplied from the decoding processing unit 56, and outputs theresulting picture to the TV 2. In the TV 2, luminance compression oneach picture is performed on the basis of the Dynamic metadata, and thepictures that have undergone luminance compression are displayed.

In step S16, the controller 51 determines whether or not random accessplayback is to be performed. If it is determined in step S16 that randomaccess playback is not to be performed, the processing returns to stepS15 to continue normal playback in which pictures are played back insequence.

On the other hand, if it is determined in step S16 that random accessplayback is to be performed, the processing goes to step S17. Forexample, if an instruction to perform fast-forward playback/rewindplayback is given by the user, or if an instruction to perform cueingplayback is given by the user, it is determined in step S16 that randomaccess playback is to be performed.

In step S17, the decoding processing unit 56 decodes the jumpdestination picture, which serves as a random access point. The picturedecoded in this step is the first picture of a GOP and Dynamic metadatais added to the first picture. The Dynamic metadata included in the SEIfor the decoded picture is supplied to the controller 51.

In step S18, the external output unit 58 adds the Dynamic metadatasupplied from the controller 51 to the picture serving as a randomaccess point, and outputs the resulting picture to the TV 2.

Thereafter, the processing returns to step S16 to repeat the foregoingprocess steps. For example, in a case where the random access playbackindicated by the user is fast-forward playback/rewind playback, thefirst pictures in their respective GOPs are played back sequentially andare output along with Dynamic metadata. For example, when the playbackof the HDR content is finished, the process in FIG. 18 is exited.

As described above, Dynamic metadata is compulsorily added to thepicture serving as a random access point. Therefore, even when randomaccess playback is to be performed, it is made possible to prevent thejump destination picture from undergoing luminance compression in amanner not intended by the producer of the HDR content.

<Example in which Dynamic Metadata is Compulsorily Added to PictureSpecified by EP_Map>

Clip Information as included in Data Base information includes theinformation called EP_map, which specifies a random access point.

HDR video data may be encoded in such a way that Dynamic metadata iscompulsorily added to the picture corresponding to the random accesspoint specified by EP_map.

FIG. 19 is a diagram illustrating an example HDR video stream includinga picture specified by EP_map as a random access point.

EP_map shown in the upper part of FIG. 19 contains descriptions aboutinformation regarding entry points (random access points): EP entry1 andEP entry2. Each of EP entry1 and EP entry2 is the information indicatingthe presentation time stamp (PTS) of the entry point and the position ofthe entry point expressed by a source packet number (SPN) on an HDRvideo stream.

In the example in FIG. 19, a picture P21 is specified by EP entry1 and apicture P22 is specified by EP entry2. Among the pictures included in anHDR video stream, Dynamic metadata is added to at least the picture P21and the picture P22, which are specified by EP entry1 and EP entry2,respectively.

For example, when an instruction to perform cueing playback startingfrom a certain entry point is given, the playback apparatus 1 outputsthe picture specified by EP entry to the TV 2 along with the Dynamicmetadata added to the picture.

In the TV 2, luminance compression on the picture specified by EP entryis performed on the basis of the Dynamic metadata transmitted along withthe picture. The picture that has undergone luminance compression isdisplayed, whereby the cueing playback is fulfilled.

In this way, Dynamic metadata may be compulsorily added to the picturespecified by EP_map included in Clip Information, which is theinformation in a file separate from HDR video streams. Therefore, it ismade possible to prevent the jump destination picture from undergoingluminance compression in a manner not intended by the producer of theHDR content.

Note that the HDR content created by multiplexing according to MP4 maybe played back by the playback apparatus 1.

The HDR content created by multiplexing according to MP4 includes an HDRvideo stream obtained by encoding HDR video data according to a certainencoding method such as AVC or HEVC, and also includes a movie fragmentrandom access box (mfra), which is playback control information for anHDR video stream.

Information indicating a random access point is included in mfra. AmongHDR video stream pictures included in MP4 HDR content, Dynamic metadatais added to at least the picture specified by the information includedin mfra. Therefore, it is also made possible to prevent the jumpdestination picture from undergoing luminance compression in a mannernot intended by the producer of the HDR content.

Such HDR content in the MP4 format is also generated by an informationprocessing apparatus having a configuration similar to the configurationillustrated in FIGS. 13 and 14. For example, an HDR video streamgenerated by the encoding processing unit 22 is multiplexed with mfragenerated by the Data Base information generation unit 33 in accordancewith the MP4 format, whereby HDR content is generated.

<About EP_Map in Clip Information>

FIG. 20 is a diagram showing the syntax of Clip Information. Thefollowing describes major descriptions included in Clip Information.

As shown in FIG. 20, Clip information includes descriptions of ClipInfo(), SequenceInfo( ), ProgramInfo ( ), CPI( ), ClipMark( ), andExtensionData( ), respectively.

ClipInfo( ) is a field in which information regarding attributes of anAV stream to be played back using Clip Information is described.

SequenceInfo( ) is a field in which information regarding a sequence ofsource packets included in an AV stream is described.

ProgramInfo( ) is a field in which information regarding a sequence ofsource packets included in a program is described.

CPI( ) is a field in which information indicating a correspondencerelationship between time and position of an AV stream is described. Adescription of EP_map is also included in CPI( ).

FIG. 21 is a diagram showing the syntax of CPI( ).

As shown in FIG. 21, CPI( ) includes descriptions of CPI_type andEP_map( ).

If the value of CPI_type is 1, CPI( ) includes information regardingEP_map.

FIG. 22 is a diagram showing the syntax of EP_map( ).

stream_PID represents the PID of a TS packet storing HDR video data.

number_of_EP_coarse_entries represents the number of EP-coarse-entriesincluded in EP_map( ). An EP-coarse-entry is information regarding anentry point with coarse accuracy in units of seconds, for example.

number_of_EP_fine_entries represents the number of EP-fine-entriesincluded in EP_map( ). An EP-fine-entry is information regarding anentry point with higher accuracy than EP-coarse-entries. An entry pointis specified by a set of an EP-coarse-entry and an EP-fine-entry.

EP_map_for_one_stream_PID includes information regarding the respectiveEP-coarse-entries and EP-fine-entries.

FIG. 23 is a diagram showing the syntax of EP_map_for_one_stream_PID.

PTS_EP_coarse[i] represents the PTS (time) of an EP-coarse-entry.

SPN_EP_coarse [i] represents the source packet (position) on an HDRvideo stream corresponding to PTS_EP_coarse [i].

PTS_EP_fine [i] represents the PTS of an EP-fine-entry.

SPN_EP_fine[i] represents the source packet on an HDR video streamcorresponding to PTS_EP_fine[i].

In the case of performing random access playback based on EP_map, theplayback apparatus 1 analyzes EP_map_for_one_stream_PID to performprocesses including the process of identifying the position of thesource packet on an HDR video stream, the source packet containing thepicture data serving as an entry point, for example. As described above,Dynamic metadata is added to the picture serving as an entry point.

<Operations of Recording Apparatus>

Referring to the flowchart in FIG. 24, the following describes arecording process in the recording apparatus 3 for adding Dynamicmetadata to the picture serving as an entry point as specified by EP_mapto generate an HDR video stream.

The process in FIG. 24 is similar to the process described withreference to FIG. 17 except that the constraint on the encoding of amaster video is different. Duplicate descriptions are omitted asappropriate.

Specifically, in step S31, the Dynamic metadata generation unit 31 inthe controller 21 sets individual parameters to specific values inaccordance with the input provided by the producer of the content andgenerates Dynamic metadata.

In step S32, the Data Base information generation unit 33 generates DataBase information including a PlayList, Clip Information containingdescriptions of EP_map, and the like. The Data Base informationgeneration unit 33 outputs information regarding each entry point (EPentry) described in EP_map to the encoding control unit 32.

In step S33, the encoding processing unit 22 encodes the master videounder the control of the encoding control unit 32 and under theconstraint that Dynamic metadata is compulsorily added to the pictureserving as the entry point specified by EP_map, and generates an HDRvideo stream.

In step S34, the disc drive 23 generates the optical disc 11 byrecording a file of the Data Base information supplied from thecontroller 21 and a file of the AV stream supplied from the encodingprocessing unit 22. Thereafter, the process is exited.

The foregoing process allows the recording apparatus 3 to generate anHDR video stream in which Dynamic metadata is added to the pictureserving as the random access point specified by EP_map, and to provideHDR content including such HDR video stream.

<Modifications>

The foregoing describes the case where Dynamic metadata is added to thefirst picture of a GOP and the case where Dynamic metadata is added tothe picture specified by EP_map, but these constraints may be used incombination.

In other words, an HDR video stream can be encoded in such a way thatDynamic metadata is compulsorily added to both the first picture of aGOP and the picture specified by EP_map.

In a case where no Dynamic metadata is added to the jump destinationpicture, the Dynamic metadata added to a picture near the jumpdestination picture may be transmitted from the playback apparatus 1 tothe TV 2 and used for luminance compression on the jump destinationpicture.

Second Embodiment (Example in which Default Metadata is Used)

<Example in which Default Metadata is Used During Random AccessPlayback>

FIG. 25 is a diagram illustrating an example of metadata transmissionoccurring during random access playback.

During random access playback, an OSD image representing specifics ofthe random access playback is combined with, for example, the jumpdestination picture in the playback apparatus 1. The picture combinedwith the OSD image is output to the TV 2 along with default metadata,which is the metadata to be used during random access playback as shownin FIG. 25, instead of Dynamic metadata.

The default metadata has parameters similar to parameters of Dynamicmetadata, such as the parameters described with reference to FIG. 3.Individual parameters of the default metadata are set to fixed valuesfor, for example, displaying various types of OSD images with suitableluminance. The default metadata is prepared in the playback apparatus 1in advance in such a manner as, for example, stored in the memory 53 inthe playback apparatus 1.

FIG. 26 is a diagram illustrating displays subsequent to luminancecompression.

For example, in a case where an instruction to perform random accessplayback such as fast-forward playback is given when a scene with higherluminance is being displayed as shown on the left side of FIG. 26, thedefault metadata is output to the TV 2 along with the jump destinationpicture combined with an OSD image.

In the TV 2, luminance compression is performed on the picture combinedwith the OSD image on the basis of the default metadata that has beentransmitted from the playback apparatus 1, resulting in the HDR videowith lowered luminance as indicated by the head of the arrow A12. Inother words, supposing that the HDR video would have the originalluminance indicated by the head of the arrow A11 after luminancecompression is performed on the basis of Dynamic metadata, the actuallydisplayed HDR video is darker than that with the original luminance.

Since suitable values for OSD images are set in the metadata, the OSDimage itself has suitable luminance as indicated by the head of thearrow A12 as a result of the luminance compression performed with thedefault metadata.

In this way, during random access playback, the default metadata is usedfor luminance compression on the jump destination picture, and thus OSDimages in the individual pictures have a constant level of luminance,whereby it is made possible to prevent OSD images from appearing to beblinking.

—Configuration and Operations of Playback Apparatus

FIG. 27 is a block diagram illustrating an example functionalconfiguration of the controller 51 applied to the case where defaultmetadata is transmitted during random access playback. The configurationof the playback apparatus 1 is the same as the configuration in FIG. 15.

In the controller 51, a Data Base information analysis unit 101, anoutput control unit 102, and a default metadata generation unit 103 areimplemented. At least part of the functional units illustrated in FIG.27 is implemented by executing a predetermined program, the executingperformed by a CPU in the controller 51.

The Data Base information analysis unit 101 analyzes the Data Baseinformation supplied from the disc drive 52 and outputs informationrepresenting the analysis result to the output control unit 102 and tothe default metadata generation unit 103. The output control unit 102and the default metadata generation unit 103 perform their respectiveprocesses by referencing the result of analysis of the Data Baseinformation as appropriate.

The output control unit 102 controls output of the HDR video bycontrolling the decoding processing unit 56 and the external output unit58.

For example, the output control unit 102 causes the decoding processingunit 56 to decode HDR video streams. Furthermore, the output controlunit 102 controls the external output unit 58 to add Dynamic metadata toeach picture obtained by decoding HDR video streams and to output theresulting picture.

When an instruction to perform random access playback is given, theoutput control unit 102 causes the decoding processing unit 56 to decodean HDR video stream and to combine the jump destination picture with anOSD image. Furthermore, the output control unit 102 controls theexternal output unit 58 to add default metadata to the picture combinedwith the OSD image and to output the resulting picture.

The default metadata generation unit 103 generates default metadata bysetting fixed values as the values of individual parameters. The defaultmetadata generation unit 103 has information regarding the fixed valuesto be set for the individual parameters. The default metadata generationunit 103 outputs the generated default metadata to, and have the defaultmetadata stored in, the memory 53.

In this way, the default metadata may be generated in the playbackapparatus 1. Alternatively, the default metadata may be stored in thememory 53 at a time when, for example, the playback apparatus 1 ismanufactured so as to be prepared in the playback apparatus 1 inadvance.

Alternatively, the user may be allowed to specify the values to be setfor individual parameters of the default metadata. In this case, valuesof individual parameters are set by using, for example, the settingscreen on the playback apparatus 1.

Furthermore, the user may be allowed to select whether the defaultmetadata transmitted from the playback apparatus 1 is to be referencedor ignored on the TV 2 side. In this case, for example, the settingscreen on the TV 2 is used to specify whether to reference or ignore thedefault metadata.

Values to be set for individual parameters of the default metadata maybe allowed to be obtained from a server.

In this case, information regarding values to be set for individualparameters of the default metadata is prepared in the server in such away that, for example, the information is associated with the HDRcontent recorded on the optical disc 11. The default metadata generationunit 103 generates the default metadata for the HDR content recorded onthe optical disc 11 by setting the values obtained from the server asthe values of individual parameters.

Furthermore, the default metadata may be allowed to be downloaded fromthe server. After downloaded and received by the communication unit 55,the default metadata is output to and stored in the memory 53.

Next, referring to the flowchart in FIG. 28, the following describes aprocess in the playback apparatus 1 that plays back HDR content in sucha way that default metadata is transmitted during random accessplayback.

The process in FIG. 28 is basically similar to the process describedwith reference to FIG. 18 except that different metadata is added toeach picture when an instruction to perform random access playback isgiven.

Specifically, in step S101, the disc drive 52 reads Data Baseinformation files including a PlayList file from the optical disc 11.

In step S102, the Data Base information analysis unit 101 in thecontroller 51 analyzes the PlayList file to, for example, identify theAV stream to be played back.

In step S103, the disc drive 52 reads, from the optical disc 11, the AVstream file that includes the HDR video stream to be played back.

In step S104, the decoding processing unit 56 decodes the HDR videostream included in the AV stream supplied from the disc drive 52, andoutputs each picture data piece to the external output unit 58. TheDynamic metadata included in the HDR video stream is supplied from thedecoding processing unit 56 to the controller 51.

In step S105, under the control of the output control unit 102, theexternal output unit 58 adds the Dynamic metadata supplied from theoutput control unit 102 to each individual picture in the HDR videosupplied from the decoding processing unit 56, and outputs the resultingpicture to the TV 2.

In step S106, the controller 51 determines whether or not random accessplayback is to be performed. If it is determined in step S106 thatrandom access playback is not to be performed, that is, if it isdetermined that normal playback is to be performed, the processingreturns to step S105 to continue outputting individual pictures in theHDR video.

On the other hand, if it is determined in step S106 that random accessplayback is to be performed, the processing goes to step S107. If aninstruction to perform fast-forward playback/rewind playback is given bythe user, or if an instruction to perform cueing playback is given bythe user, it is determined in step S106 that random access playback isto be performed.

In step S107, the decoding processing unit 56 decodes the jumpdestination picture, which serves as a random access point.

In step S108, the decoding processing unit 56 combines the jumpdestination picture with an OSD image.

In step S109, the external output unit 58 adds default metadata to thejump destination picture combined with the OSD image and outputs theresulting picture. The default metadata that is output along with thejump destination picture is supplied from the output control unit 102 inthe controller 51.

Thereafter, the processing returns to step S106 to repeat the foregoingprocess steps. For example, in a case where the random access playbackindicated by the user is fast-forward playback/rewind playback, firstpictures in GOPs are sequentially decoded, and these first pictures intheir respective GOPs are output along with default metadata.

—Operations of TV

Next, referring to the flowchart in FIG. 29, the following describes adisplay process in the TV 2.

The process in FIG. 29 is performed when transmission of the pictureobtained by decoding an HDR video stream is started. The picturetransmitted from the playback apparatus 1 includes either Dynamicmetadata or default metadata added thereto.

In step S121, the external input unit 72 in the TV 2 receives eachpicture data piece in the HDR video that has been transmitted from theplayback apparatus 1, and also receives the Dynamic metadata or thedefault metadata that is added thereto and that has been transmitted.

If an instruction to perform random access playback is not given, eachpicture is received along with Dynamic metadata in this step. On theother hand, if an instruction to perform random access playback is givento the playback apparatus 1, a picture combined with an OSD image isreceived along with default metadata in this step.

Each picture data piece received by the external input unit 72 issupplied to the signal processing unit 73, and the metadata (eitherDynamic metadata or default metadata) is supplied to the controller 71.

In step S122, the signal processing unit 73 performs luminancecompression on each picture in the HDR video under the control of thecontroller 71. If the metadata transmitted along with a picture isDynamic metadata, luminance compression is performed on the basis of theDynamic metadata. On the other hand, if the metadata transmitted alongwith a picture is default metadata, luminance compression is performedon the basis of the default metadata.

In step S123, the signal processing unit 73 causes the display 74 todisplay the picture that has undergone luminance compression. Displayingthe HDR video including such sequence of process steps is continueduntil playback of the HDR content is finished.

As described above, by performing luminance compression in the TV 2 onthe basis of default metadata during random access playback, it is madepossible to prevent the OSD image combined with each picture fromappearing to be blinking.

<Example in which Default Metadata is Used when Jump Destination has NoDynamic Metadata>

Instead of compulsorily using default metadata when random accessplayback is performed, the default metadata may be used and transmittedto the TV 2 if the jump destination picture has no Dynamic metadataadded thereto.

FIG. 30 is a diagram illustrating an example of random access playback.

As an example, the following describes the case where an instruction toperform cueing playback is given at a time when the picture P1 is aboutto be played back, and a jump is made from the picture P1 to the pictureP2 as indicated by the arrow A1 in FIG. 30.

In this case, the playback apparatus 1 analyzes the picture P2 anddetects whether or not Dynamic metadata is added thereto. If the pictureP2 is within a section in which no Dynamic metadata is added, defaultmetadata is used and output along with the picture P2.

For example, if Dynamic metadata is added to the picture P2, the Dynamicmetadata is output along with the picture P2.

As seen above, Dynamic metadata may be transmitted if the Dynamicmetadata is added to the jump destination picture, while defaultmetadata may be transmitted if Dynamic metadata is not added to the jumpdestination picture.

Now, referring to the flowchart in FIG. 31, the following describes aprocess in the playback apparatus 1 that plays back HDR content.

The process in FIG. 31 is similar to the process in FIG. 28 except thatthe metadata to be transmitted to the TV 2 is switched according towhether or not Dynamic metadata is added to the jump destinationpicture.

Specifically, in steps S131 to S135, HDR content is normally played backas in steps S101 to S105 in FIG. 28.

If it is determined that random access playback is to be performed instep S136, the decoding processing unit 56 decodes the jump destinationpicture serving as a random access point in step S137.

In step S138, the decoding processing unit 56 combines the jumpdestination picture with an OSD image.

In step S139, the decoding processing unit 56 determines whether or notDynamic metadata is added to the jump destination picture.

If it is determined in step S139 that Dynamic metadata is not addedthereto, the external output unit 58 adds default metadata to the jumpdestination picture combined with the OSD image and outputs theresulting picture in step S140.

On the other hand, if it is determined in step S139 that Dynamicmetadata is added thereto, the external output unit 58 adds Dynamicmetadata to the jump destination picture combined with the OSD image andoutputs the resulting picture in step S141.

After the picture is output in step S140 or step S141, the processingreturns to step S136 to repeat the foregoing process steps.

In this way, the default metadata may be used only in a case where noDynamic metadata is added to the jump destination picture, while Dynamicmetadata may be transmitted to the TV 2 if the Dynamic metadata is addedthereto. Therefore, luminance compression on the jump destinationpicture can be performed in a manner intended by the producer of the HDRcontent.

Example Configuration of Playback System First Example Configuration

Descriptions above have been provided about the case where HDR contentis recorded on the optical disc 11. However, the foregoing processes canalso be applied to a case where HDR content distributed via a network isplayed back as described above.

FIG. 32 is a diagram illustrating an example configuration of an HDRcontent playback system.

The playback system in FIG. 32 is configured by connecting the playbackapparatus 1 to a content distribution server 301 via a network 302 suchas the Internet. The TV 2 is connected to the playback apparatus 1 viaan HDMI cable or the like. Video images of the HDR content played backby the playback apparatus 1 are displayed on the TV 2.

The content distribution server 301 is a server managed by a businessoperator providing HDR content distribution services. The contentdistributed by the content distribution server 301 is HDR content.

Each HDR content piece is made by associating an HDR video stream fileincluding Dynamic metadata with a playback control information file.

For example, when the user operates the playback apparatus 1 to accessthe content distribution server 301, an HDR content selection screen isdisplayed on the TV 2. The user can select a certain HDR content pieceand send a request to the content distribution server 301 so that theuser can start viewing of the content.

When some HDR content is selected, the content distribution server 301sends the selected HDR content to the playback apparatus 1.

The playback apparatus 1 receives the HDR content sent from the contentdistribution server 301 and plays back the HDR content by performing aprocess similar to the above-described playback process.

In other words, the playback apparatus 1 transmits each individualpicture to the TV 2 along with Dynamic metadata, the individual picturesbeing obtained by decoding HDR video streams, and luminance compressionis performed on the basis of the Dynamic metadata.

Furthermore, when an instruction to perform random access playback isgiven, each picture in the HDR video is transmitted along with theDynamic metadata that is added to the jump destination picture, and, inthe TV 2, luminance compression is performed on the basis of the Dynamicmetadata. Dynamic metadata is added to the jump destination picture,which is the first picture of a GOP or the picture specified by EP_mapor the like as an entry point.

Moreover, in a case where default metadata is prepared in the playbackapparatus 1, in response to an instruction to perform random accessplayback, the default metadata is transmitted along with the jumpdestination picture, and, in the TV 2, luminance compression isperformed on the basis of the default metadata.

As described above, the content distribution server 301 may distributethe HDR content that includes HDR video streams in which Dynamicmetadata is compulsorily added to the first picture of a GOP or to thepicture specified as an entry point.

Furthermore, when random access playback of an HDR video stream includedin the HDR content distributed by the content distribution server 301 isto be performed, default metadata may be output from the playbackapparatus 1 to the TV 2.

FIG. 33 is a diagram illustrating another example configuration of theplayback apparatus 1.

As illustrated in FIG. 33, the playback apparatus 1 may be a so-calledstick type terminal. An HDMI terminal is disposed on the housing of theplayback apparatus 1 illustrated in FIG. 33. The HDMI terminal disposedon the housing is inserted into the HDMI terminal on the TV 2, wherebythe playback apparatus 1 and the TV 2 are connected.

For example, the playback apparatus 1 in FIG. 33 is in the configurationillustrated in FIG. 15 excluding the disc drive 52. The playbackapparatus 1 plays back the HDR content distributed by the contentdistribution server 301 by performing a process similar to theabove-described process.

As described above, a variety of forms can be employed as the form ofthe playback apparatus 1. For example, functions of the playbackapparatus 1 may be provided on a portable terminal such as a smartphoneor tablet terminal, or function of the playback apparatus 1 may beprovided on a terminal such as a PC.

Second Example Configuration

Functions of the playback apparatus 1 may be provided on the TV 2.

FIG. 34 is a diagram illustrating an example configuration of anotherHDR content playback system.

The playback system in FIG. 34 is configured by connecting the TV 2 onwhich functions of the playback apparatus 1 are provided and the contentdistribution server 301 via the network 302. Duplicate descriptions areomitted as appropriate.

The TV 2 displays an HDR content selection screen on the basis of theinformation sent from the content distribution server 301.

When a certain HDR content piece is selected by the user, the contentdistribution server 301 sends the selected HDR content to the TV 2.

The TV 2 receives the HDR content sent from the content distributionserver 301 and plays back the HDR content.

That is, the TV 2 performs luminance compression on each picture in theHDR video on the basis of Dynamic metadata.

Furthermore, when an instruction to perform random access playback isgiven, luminance compression is performed on the jump destinationpicture on the basis of the Dynamic metadata added to the jumpdestination picture.

Moreover, in a case where default metadata is prepared in the TV 2, whenan instruction to perform random access playback is given, luminancecompression is performed on the jump destination picture on the basis ofthe default metadata.

As seen above, functions of the playback apparatus 1 may be provided onthe TV 2, and the process as described above may be performed in the TV2.

Other Examples

The foregoing assumes that the recording medium for HDR content is anoptical disc, but the recording medium may be another recording mediumsuch as a flash memory.

The foregoing assumes that the process performed on a video on the basisof Dynamic metadata or default metadata is luminance compression, butluminance expansion may be performed in the TV 2. In this case, Dynamicmetadata or default metadata contains descriptions about tone curveinformation used for luminance expansion.

The foregoing assumes that video streams to be input to the playbackapparatus 1 are the video streams encoded by a predetermined method, butthe video streams that include pictures to which Dynamic metadata isadded and that are not encoded may be input to the playback apparatus 1.

<Example Configuration of Computer>

The aforementioned series of process steps can be executed by hardwareor executed by software. In a case where the series of process steps isto be executed by software, programs included in the software areinstalled from a program recording medium onto a computer incorporatedinto special-purpose hardware, a general-purpose computer, or the like.

FIG. 35 is a block diagram illustrating an example hardwareconfiguration of a computer in which the aforementioned series ofprocess step is executed by programs.

A central processing unit (CPU) 1001, a read only memory (ROM) 1002, anda random access memory (RAM) 1003 are connected to one another by a bus1004.

Moreover, an input/output interface 1005 is connected to the bus 1004.To the input/output interface 1005, an input unit 1006 including akeyboard, a mouse, or the like and an output unit 1007 including adisplay, a speaker, or the like are connected. Furthermore, to theinput/output interface 1005, a storage unit 1008 including a hard disc,a non-volatile memory, or the like, a communication unit 1009 includinga network interface or the like, and a drive 1010 that drives aremovable medium 1011 are connected.

In the computer configured as above, the CPU 1001 performs theaforementioned series of process steps by, for example, loading aprogram stored in the storage unit 1008 into the RAM 1003 via theinput/output interface 1005 and the bus 1004 and executing the program.

Programs to be executed by the CPU 1001 are recorded on, for example,the removable medium 1011 or provided via a wired or wirelesstransmission medium such as a local area network, the Internet, ordigital broadcasting, and installed on the storage unit 1008.

Note that the programs executed by the computer may be programs forprocess steps to be performed in time series in the order describedherein, or may be programs for process steps to be performed in parallelor on an as-needed basis when, for example, a call is made.

Embodiments of the present technology are not limited to theabove-described embodiments, and various modifications can be madethereto to the extent not departing from the gist of the presenttechnology.

For example, the present technology can be in a cloud computingconfiguration in which one function is distributed among, and handled incollaboration by, a plurality of apparatuses via a network.

Furthermore, each of the steps described above with reference to theflowcharts can be executed not only by one apparatus but also by aplurality of apparatuses in a shared manner.

Moreover, in a case where one step includes a plurality of processes,the plurality of processes included in the one step can be executed notonly by one apparatus but also by a plurality of apparatuses in a sharedmanner.

A system herein means a set of a plurality of components (apparatuses,modules (parts), and the like) regardless of whether or not all thecomponents are within the same housing. Therefore, either of a pluralityof apparatuses contained in separate housings and connected via anetwork and one apparatus in which a plurality of modules is containedin one housing is a system.

The effects described herein are examples only and are not restrictive,and other effects may be provided.

<Examples of Configuration Combination>

The present technology can be in any of the following configurations.

(1)

An information processing apparatus including:

a generation unit that generates dynamic metadata including informationregarding luminance of a picture; and

an encoding unit that encodes HDR video data such that the dynamicmetadata is added to each picture serving as a random access point.

(2)

The information processing apparatus according to (1), in which

the encoding unit adds the dynamic metadata to a first picture of a GOPas the picture serving as the random access point.

(3)

The information processing apparatus according to (1), furtherincluding:

a generation unit that generates playback control information includinginformation specifying the random access point, the playback controlinformation being used for playing back a video stream obtained by theencoding, in which

the encoding unit adds the dynamic metadata to the picture serving asthe random access point specified by the information included in theplayback control information.

(4)

The information processing apparatus according to (3), in which

the information specifying the random access points is EP_map includedin Clip Information, the Clip Information being defined by a Blu-rayDisc format and serving as the playback control information, and

the encoding unit adds the dynamic metadata to each picture serving asan entry point specified in the EP_map as the random access point.

(5)

The information processing apparatus according to (3), in which

the information specifying the random access point is Movie FragmentRandom Access Box, the Movie Fragment Random Access Box being defined byan MP4 format and serving as the playback control information, and

the encoding unit adds the dynamic metadata to each picture serving asthe random access point specified by the Movie Fragment Random AccessBox.

(6)

An information processing method, in which

an information processing apparatus

generates dynamic metadata including information regarding luminance ofa picture, and

encodes HDR video data such that the dynamic metadata is added to eachpicture serving as a random access point.

(7)

A program configured to cause a computer to execute processes of:

generating dynamic metadata including information regarding luminance ofa picture; and

encoding HDR video data such that the dynamic metadata is added to eachpicture serving as a random access point.

(8)

A recording medium, in which

a video stream generated by encoding HDR video data such that dynamicmetadata including luminance information is added to each pictureserving as a random access point is recorded.

(9)

A playback apparatus including:

a playback unit that performs random access playback of a video streamgenerated by encoding HDR video data such that dynamic metadataincluding luminance information is added to each picture serving as arandom access point; and

an output control unit that outputs the picture serving as the randomaccess point to a display apparatus along with the dynamic metadata.

(10)

A playback apparatus including:

a playback unit that performs random access playback of a video streamto which dynamic metadata including information regarding luminance of apicture is added; and

an output control unit that, in a case where predetermined informationindicating that random access playback is being performed is to besuperimposed on the picture and displayed, adds metadata to be usedduring random access playback for luminance adjustment during the randomaccess playback to the picture serving as a random access point, andoutputs the picture to which the metadata to be used during the randomaccess playback is added to a display apparatus.

(11)

The playback apparatus according to (10), in which

the playback unit performs, as the random access playback, fast-forwardplayback or rewind playback at x-fold speed, where x is a predeterminednumber.

(12)

The playback apparatus according to (10) or (11), in which

the playback unit performs cueing playback as the random accessplayback.

(13)

A playback method, in which

a playback apparatus

performs random access playback of a video stream to which dynamicmetadata including information regarding luminance of a picture isadded,

in a case where predetermined information indicating that random accessplayback is being performed is to be superimposed on the picture anddisplayed, adds metadata to be used during random access playback forluminance adjustment during the random access playback to the pictureserving as a random access point, and

outputs the picture to which the metadata to be used during the randomaccess playback is added to a display apparatus.

(14)

A program configured to cause a computer to execute processes of:

performing random access playback of a video stream to which dynamicmetadata including information regarding luminance of a picture isadded;

in a case where predetermined information indicating that random accessplayback is being performed is to be superimposed on the picture anddisplayed, adding metadata to be used during random access playback forluminance adjustment during the random access playback to the pictureserving as a random access point; and

outputting the picture to which the metadata to be used during therandom access playback is added to a display apparatus.

REFERENCE SIGNS LIST

-   1 Playback apparatus-   2 TV-   3 Recording apparatus-   21 Controller-   22 Encoding processing unit-   23 Disc drive-   31 Dynamic metadata generation unit-   32 Encoding control unit-   33 Data Base information generation unit-   34 Recording control unit-   51 Controller-   52 Disc drive-   53 Memory-   54 Local storage-   55 Communication unit-   56 Decoding processing unit-   57 Operation input unit-   58 External output unit-   101 Data Base information analysis unit-   102 Output control unit-   103 Default metadata generation unit

1. An information processing apparatus comprising: a generation unitthat generates dynamic metadata including information regardingluminance of a picture; and an encoding unit that encodes HDR video datasuch that the dynamic metadata is added to each picture serving as arandom access point.
 2. The information processing apparatus accordingto claim 1, wherein the encoding unit adds the dynamic metadata to afirst picture of a GOP as the picture serving as the random accesspoint.
 3. The information processing apparatus according to claim 1,further comprising: a generation unit that generates playback controlinformation including information specifying the random access point,the playback control information being used for playing back a videostream obtained by the encoding, wherein the encoding unit adds thedynamic metadata to the picture serving as the random access pointspecified by the information included in the playback controlinformation.
 4. The information processing apparatus according to claim3, wherein the information specifying the random access points is EP_mapincluded in Clip Information, the Clip Information being defined by aBlu-ray Disc format and serving as the playback control information, andthe encoding unit adds the dynamic metadata to each picture serving asan entry point specified in the EP_map as the random access point. 5.The information processing apparatus according to claim 3, wherein theinformation specifying the random access point is Movie Fragment RandomAccess Box, the Movie Fragment Random Access Box being defined by an MP4format and serving as the playback control information, and the encodingunit adds the dynamic metadata to each picture serving as the randomaccess point specified by the Movie Fragment Random Access Box.
 6. Aninformation processing method, wherein an information processingapparatus generates dynamic metadata including information regardingluminance of a picture, and encodes HDR video data such that the dynamicmetadata is added to each picture serving as a random access point.
 7. Aprogram configured to cause a computer to execute processes of:generating dynamic metadata including information regarding luminance ofa picture; and encoding HDR video data such that the dynamic metadata isadded to each picture serving as a random access point.
 8. A recordingmedium, wherein a video stream generated by encoding HDR video data suchthat dynamic metadata including luminance information is added to eachpicture serving as a random access point is recorded.
 9. A playbackapparatus comprising: a playback unit that performs random accessplayback of a video stream generated by encoding HDR video data suchthat dynamic metadata including luminance information is added to eachpicture serving as a random access point; and an output control unitthat outputs the picture serving as the random access point to a displayapparatus along with the dynamic metadata.
 10. A playback apparatuscomprising: a playback unit that performs random access playback of avideo stream to which dynamic metadata including information regardingluminance of a picture is added; and an output control unit that, in acase where predetermined information indicating that random accessplayback is being performed is to be superimposed on the picture anddisplayed, adds metadata to be used during random access playback forluminance adjustment during the random access playback to the pictureserving as a random access point, and outputs the picture to which themetadata to be used during the random access playback is added to adisplay apparatus.
 11. The playback apparatus according to claim 10,wherein the playback unit performs, as the random access playback,fast-forward playback or rewind playback at x-fold speed, where x is apredetermined number.
 12. The playback apparatus according to claim 10,wherein the playback unit performs cueing playback as the random accessplayback.
 13. A playback method, wherein a playback apparatus performsrandom access playback of a video stream to which dynamic metadataincluding information regarding luminance of a picture is added, in acase where predetermined information indicating that random accessplayback is being performed is to be superimposed on the picture anddisplayed, adds metadata to be used during random access playback forluminance adjustment during the random access playback to the pictureserving as a random access point, and outputs the picture to which themetadata to be used during the random access playback is added to adisplay apparatus.
 14. A program configured to cause a computer toexecute processes of: performing random access playback of a videostream to which dynamic metadata including information regardingluminance of a picture is added; in a case where predeterminedinformation indicating that random access playback is being performed isto be superimposed on the picture and displayed, adding metadata to beused during random access playback for luminance adjustment during therandom access playback to the picture serving as a random access point;and outputting the picture to which the metadata to be used during therandom access playback is added to a display apparatus.